ILL practitioners are confronted with complexity and overload caused by ILL/DD (Interlibrary Loan/Document Delivery) systems or interfaces, that have been developed lately due to users’ increasing demands and thanks to ICT advances. Since this multiplicity hinders the function and the effectiveness of ILL Service, there has emerged the imperative of integrating diverse ILL systems into one. A unified ILL service will enable practitioners to work with a simple and easy-to-follow interface and will allow users to experience a one-stop ILL Service, which may be eventually developed into one-stop Library Service. This paper aims to present the newly formed requirements, emerging from a composite ILL environment, as well as, an Intelligent Middleware Platform for unified ILL Services, which is a response to the current ILL service challenges. More specific, current ILL service challenges and demands are discussed on the one hand, and why one-stop library service concept should be taken into consideration as an effective response to them, is explained on the other hand. Following this, a series of ILL integrated software systems, that has emerged lately, is briefly presented. Furthermore, composite ILL architectures, as well as, the newly derived high level requirements, with regard to ILL systems, are described in the paragraphs that follow. This presentation takes place in order to allow an informed comparison with smILLe middleware approach. Finally, smILLe (Veranis, 2010) middleware approach and system are explicitly presented, along with basic workflow examples and the system’s pertinent screenshots.